Many arrangements have been provided in the past for mounting an electric motor in a housing, such as the housing or frame of a fan, air conditioner or furnace. Usually the shell of the motor is connected directly to the housing by mounting lugs or arms which support both the motor and the blower wheel or blades. In some instances a relatively rigid mount is provided, and U.S. Pat. Nos. 1,781,155, 2,936,949 and 3,775,029 show constructions representative of this type.
In another type of mount, relatively flexible mounting lugs connect the motor to the housing, and the following U.S. patents show representative constructions:
______________________________________ 1,873,343 1,935,179 1,971,327 2,081,030 2,096,621 2,451,970 2,615,620 3,143,284 3,145,910 3,317,124 3,506,226 3,773,285 3,803,690 4,063,060 4,076,197 4,293,114 4,323,217 ______________________________________
The function of the flexible lugs is to provide torsional isolation of the motor from the housing in order to prevent vibrations and/or pulsations of the motor from being passed to the housing. In some instances the flexible lugs are attached directly to the motor shell and in other instances the lugs are attached to a circular strap or belly band which in turn is attached to the shell.
It is preferred that the flexible lugs be made of spring metal in order to obtain sufficient fatigue strength as well as torsional isolation, but problems have been encountered in the connection between spring metal lugs and the motor. In some constructions, such as those shown in U.S. Pat. Nos. 4,063,060 and 4,076,197, the lugs have been fastened by weld connections; great care must be taken to prevent the heat of welding from removing the temper from the lug metal, and expedients to prevent this have been relatively expensive and have proven to be unreliable over a long period of time.
Other constructions including spring metal lugs have employed mechanical connections between the lugs and the motor, such as shown in U.S. Pat. Nos. 4,293,114 and 4,323,217, but again these have been relatively expensive to manufacture. Further, in the structure shown in U.S. Pat. No. 4,293,114, the motor cannot be grounded through the mounting lugs, and in U.S. Pat. No. 4,323,217 a truly rigid connection is not obtained. U.S. Pat. No. 2,451,970 shows a mount wherein mechanical connections are made to the outer periphery of a motor, but such an arrangement would be expensive to manufacture and could not be used where the motor shell consists of a thin tubular metal part that fits tightly against the stator laminations, because the mechanical fasteners extend into the interior of the motor.
It is a general object of the present invention to provide an improved motor mount which avoids the foregoing problems and provides secure and relatively inexpensive connections.